NASA says a drought like no other we have seen in the past 1000 years is due to the western part of the United States if greenhouse gas emissions keep going the way they are. Those regions have suffered severe drought in recent years. But it doesn’t compare in the slightest to the ‘megadroughts’ likely to hit them before the century is over due to global warming. These will be epochal, worthy of a chapter in Earth’s natural history. Even if emissions drop moderately, droughts in those regions will get much worse than they are now, NASA said.